Intraoral dental radiology positioning device for use with aiming ring

ABSTRACT

A receptor positioning device for taking dental bitewing radiographs of a patient&#39;s teeth comprises a receptor holding member adapted to receive a receptor for exposing x-radiation from the x-ray machine and a collimation plate having a substantially flat surface for aligning with an x-ray machine. The collimation plate has a rectangular opening in its surface for passage of radiation from the x-ray machine to expose a receptor in the receptor holding member and a pair of handles extending away from the plate for positioning the device. The collimation plate is constructed of metal having a thickness of at least 0.075 in., preferably at least 0.100 in., to reduce the passage of radiation from the x-ray machine to the patient except at the plate opening. The device also includes an arm between the collimation plate and the receptor holding member, the arm including a biting surface for engaging the patient&#39;s teeth to secure the device in the patient&#39;s mouth, and an aiming ring secured to the arm at a position distal from the receptor holding member, with the collimation plate being secured to the aiming ring. The aiming ring may also include notches and the collimation plate preferably includes clips for removably securing the plate to the aiming ring and tabs for locating the plate relative to the aiming ring notches.

This application is related to an application by the same inventor filedon even date herewith as attorney's docket no. DEDE130001000 entitled“Intraoral Dental Radiology Positioning Device.”

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to devices for dental radiographicprocedures or intraoral diagnostics, and more particularly, to intraoraldental radiology positioning devices relating to positioning x-ray filmor receptors in a patient's mouth during radiographic procedures.

2. Description of Related Art

Intraoral x-ray diagnosis involves positioning an x-ray film within apatient's mouth next to the inner surface of the teeth or bone beingstudied. The film is then exposed to an x-ray beam generated outside themouth and passing through the target. Known intraoral dental radiographytypically employs a dental device having an alignment member includingan x-ray film holding structure at one end, an aligning arm at anotherend, and a bite plate positioned between the ends. The alignment member(also known as an aiming ring) may include a collimation structure forcollimation of an x-ray beam to conform more accurately to the size andshape of the x-ray film held by the film holding structure. A commonlyprescribed dental radiograph is the “bitewing”, whereby an image isacquired of the crowns of the teeth biting together and theirsurrounding socket bone. Also typical is film mounted in a holder whichincludes a bite block portion extending from the film in the directionof the external x-ray tube. The patient bites down on the bite blockwith the target teeth and holds the film in position next to the target.

Many dental radiographic techniques utilize beams of circularcross-section despite the fact that the dental films are typicallyrectangular in shape. A disadvantage of known devices is that thecross-sectional area of the beam used by the radiographic technique istypically larger than the surface area of the x-ray film. When thecross-sectional area of the beam does not match the film size, thepatient can be exposed to unnecessary radiation which irradiates tissuesbeyond the borders of the dental film. Typical film positioninginstruments may also allow unwanted x-radiation to pass through the filmholding instrument.

Another disadvantage of current x-ray film positioning instruments isthat there can be errors in aiming the x-ray. These errors arefrequently associated with a rectangular position-indicating deviceattached to an x-ray machine. Also, there can be errors in orientationof the long axis of the substantially rectangular typical positionindicating devices with the long axis of the film in the patient'smouth. Aiming and orientation errors expose the patient to needlessretakes of radiographs.

Typical film positioning devices and instruments include multiple parts,requiring assembly and adjustment. The multiple arrangements of partsmay lose their set position which can cause a reduction in the sharpnessof the acquired image.

Enhancing the ability to sterilize dental equipment is desirable in thefield. Current film positioning devices may have disadvantages whensterilizing because parts, such as cushioned areas, may be lessaccessible or receptive to steam, heat or chemical methods. Difficultyin disinfecting or sterilizing is associated with a rectangularpositioning indicating device attached to an x-ray machine

Another disadvantage of current x-ray film positioning instruments isthat the patient can only bite on the bite plate to assist inpositioning and holding a film positioning device in the mouth. Typicaldevices may be difficult to grasp and manipulate in the patient's mouthmaking it problematic for the patient to assist in positioning theinstrument.

Bearing in mind the problems and deficiencies of the prior art, it istherefore an object of the present invention to provide a device whichwill reduce patient exposure of x-radiation.

It is a further object of the present invention to provide a devicewhich will reduce aiming error and cone cuts.

It is another object of the invention to provide a device which willimprove the quality of the acquired image on the receptor-x-ray film.

It is yet another object of the present invention to provide a devicewhich will universally adapt to traditional film and electronic/digitalreceptors, and also to typical film holding instrument aiming rings.

It is a further object of the present invention to provide a devicewhich will minimize movement of the interconnected parts of the deviceonce the parts are desirably positioned.

It is another object of the present invention to provide a device whichminimizes movement of the device in the patient's mouth.

It is yet another object of the present invention to provide a devicewhich precisely sets the x-ray source to align with the receptor, orfilm.

It is a further object of the present invention to provide a devicewhich limits magnification and keeps magnification uniform.

It is another object of the present invention to provide a device whichmaximizes sharpness of the acquired image on the film.

It is a further object of the present invention to provide a devicewhich facilitates sterilization.

It is another object of the present invention to provide a device whichis of maximum durability.

It is yet another object of the present invention to provide a devicewhich minimizes patient discomfort and malpositioning.

It is a further object of the present invention to provide a devicewhich minimizes “retakes” of radiographs.

It is another object of the present invention to provide a method ofpositioning a film-positioning device in a patient's mouth providing anunobstructed line between an x-ray device and x-ray film.

It is another object of the present invention to provide a device whichcan rotate the orientation of the central rectangular opening of acollimator.

Still other objects and advantages of the invention will in part beobvious and will in part be apparent from the specification.

SUMMARY OF THE INVENTION

The above and other objects, which will be apparent to those skilled inart, are achieved in the present invention which is directed to, in afirst aspect, a receptor positioning device for taking dental bitewingradiographs of a patient's teeth, which comprises a receptor holdingmember adapted to receive a receptor for exposing x-radiation from thex-ray machine and a collimation plate having a substantially flatsurface for aligning with an x-ray machine. The collimation plate has anopening in its surface, preferably rectangular, for passage of radiationfrom the x-ray machine to expose a receptor in the receptor holdingmember and a handle extending away from the plate for positioning thedevice. The collimation plate is constructed of metal having a thicknessof at least 0.075 in., preferably at least 0.100 in., to reduce thepassage of radiation from the x-ray machine to the patient except at theplate opening. The device also includes an arm between the collimationplate and the receptor holding member, the arm including a bitingsurface for engaging the patient's teeth to secure the device in thepatient's mouth.

In a related aspect, the present invention is directed to a method fortaking dental bitewing radiographs of a patient's teeth comprisingproviding a receptor positioning device of the type described above, andproviding a receptor on the receptor holding member. The method thenincludes positioning the receptor holding member in the patient's mouthand the patient's teeth on the biting surface to secure the device inthe patient's mouth, adjusting the position of receptor positioningdevice by grasping the handle extending from the collimation plate,aligning an x-ray machine with the substantially flat surface of thecollimation plate, and passing radiation from the x-ray machine throughthe opening of the collimation plate while substantially blockingpassage of radiation through the collimation plate thickness to exposethe receptor.

The device includes an aiming ring secured to the arm at a positiondistal from the receptor holding member, and the method includessecuring the collimation plate to the aiming ring. The aiming ring mayinclude notches and the collimation plate preferably includes clips forremovably securing the plate to the aiming ring and tabs for locatingthe plate relative to the aiming ring notches. The method then includesbending the clips to secure the collimation plate to the aiming ring andinserting the collimation plate tabs into the aiming ring notches.

The device preferably includes a pair of handles extending from thecollimation plate, which handles may be opposite each other or atapproximately a right angle to each other. The method then includesgrasping the handles to adjust the position of receptor positioningdevice.

In another aspect, the present invention is directed to a receptorpositioning device for taking dental bitewing radiographs of a patient'steeth comprising a collimation plate defining a substantially centralopening. A receptor holding member is adapted to receive a receptor, andan elongated arm including a biting surface is positioned toward adistal end thereof. The elongated arm is adapted to receive and coupleat a first end to the collimation plate. The elongated arm is designedand adapted to extend towards and couple to a rear portion of thereceptor holding member, opposite the collimation plate, such that anunobstructed path is defined between the substantially central openingof the collimation plate and the receptor received by the receptorholding member. The receptor holding member may preferably accommodate aplurality of receptor dimensions, films, and digital receptors. In apreferred embodiment of the present invention, the collimation plate,the receptor holding member, and the elongated arm are rigidly fixedtogether. In another preferred embodiment of the present invention, thecollimation plate, the receptor back plate, and the elongated arm areconstructed of metal.

In a related aspect, the present invention is directed to a receptorpositioning device for taking dental bitewing radiographs of a patient'steeth, which comprises a collimation plate having an opening therein foraligning an x-ray machine and a receptor holding member adapted toreceive a receptor for exposing x-radiation from the x-ray machine. Anelongated arm is coupled at a first end to the collimation plate andincludes a biting surface positioned toward a distal end thereof. Theelongated arm from the biting portion distal end further extends towardsthe collimation plate and is coupled to the receptor holding member,such that an unobstructed path is defined between the substantiallycentral opening of the collimation plate and the receptor received bythe receptor holding member while the patient's teeth engage the bitingportion distal end.

The biting portion distal end on the elongated arm, adjacent thereceptor back plate, may include an incompressible receiving portionadapted for biting with the patient's teeth. Optionally, the bitingportion distal end includes an elastomeric impression material adaptedfor creating and registering with an occlusion pattern of the patient'steeth. Openings in the biting portion distal end permit the elastomericimpression material to couple to the distal end surface.

The collimation plate may include handles opposite of one another forthe patient to grasp. The opening in the collimation plate is preferablysubstantially rectangular in shape, is orientated similarly to the filmhaving a substantially rectangular shape, and the substantially centralopening defined by the collimation plate is adapted to corresponddimensionally to the dimensions of the receptor. Preferably, thecollimation plate is constructed of metal having a thickness of at least0.075 in. to prevent overexposing the patient to needless additionalradiation.

In another related aspect, the biting surface is adjacent to thereceptor holding member such that the receptor is positioned behind thepatient's teeth. The receptor holding member may include notches in anedge for receiving at least one band to secure together the receptor andholding member. Where the receptor is a digital receptor having a datacord, there may be further included a connector securing the data cordto the elongated arm between the collimation plate and the receptorholding member.

In another aspect of the present invention, a receptor positioningdevice for taking dental bitewing radiographs of teeth inside apatient's mouth, comprises a rigid, fixed structure including acollimation plate defining a substantially rectangular opening, areceptor holding member adapted to receive a receptor, and an elongatedarm being adapted to receive and couple at a first end to thecollimation plate. The elongated arm is designed and adapted to extendtowards and couple at a second end to a rear portion of the receptorholding member, opposite the collimation plate, such that anunobstructed path is defined between the substantially rectangularopening of the collimation plate and the receptor received by thereceptor holding member. A biting surface is fixedly attached to adistal end of the elongated arm and adjacent to the receptor holdingmember such that the receptor is positioned behind the teeth on whichthe radiographs being taken while the biting surface is gripped by teethon the opposite side of the patient's mouth.

In yet another aspect of the present invention, a method for takingdental bitewing radiographs of a patients' teeth comprises initiallyproviding a receptor positioning device of the type describe above.Preferably, the device is a rigid, fixed structure including acollimation plate defining a substantially central opening, a receptorholding member adapted to receive a receptor, and an elongated arm beingadapted to receive and couple at a first end to the collimation plate.The elongated arm is designed and adapted to extend towards and coupleto a rear portion of the receptor holding member such that anunobstructed path is defined between the substantially rectangularopening of the collimation plate and the receptor received by thereceptor holding member. A biting surface is provided which is fixedlyattached to a distal end of the elongated arm and adjacent to thereceptor holding member such that the receptor is positioned behind thepatient's teeth on which the radiographs is being taken while the bitingsurface is gripped by teeth on the opposite side of the patient's mouth.The patient's teeth bite on the biting surface such that an unobstructedx-ray path is defined between the collimation plate and the receptorreceived by the receptor holding member. An x-ray machine is alignedwith the opening of the collimation plate, and the receptor is exposedsuch that x-radiation from the x-ray machine passes along theunobstructed path defined between the collimation plate and thereceptor.

BRIEF DESCRIPTION OF THE DRAWINGS

The features of the invention believed to be novel and the elementscharacteristic of the invention are set forth with particularity in theappended claims. The figures are for illustration purposes only and arenot drawn to scale. The invention itself, however, both as toorganization and method of operation, may best be understood byreference to the detailed description which follows taken in conjunctionwith the accompanying drawings in which:

FIG. 1 is a perspective view of the receptor positioning device of thepresent invention.

FIG. 2 is a front elevational view of the collimation plate of thedevice shown in FIG. 1.

FIG. 3 is a side elevational view of the receptor positioning deviceshown in FIG. 1 depicting the position of the patient's teeth.

FIG. 4 is another side view of the receptor positioning device shown inFIG. 1 rotated 180° from the view in FIG. 3.

FIG. 5 is a side elevational view of the elongated arm of the receptorpositioning device shown in FIG. 1.

FIG. 6 is a side view of the elongated arm of FIG. 5.

FIG. 7 is a side elevational view of another embodiment of an elongatedarm of the receptor positioning device shown in FIG. 1

FIG. 8 is a side view of the elongated arm of FIG. 7.

FIG. 9 is a front elevational view of another collimation plate for usewith the receptor positioning device shown in FIG. 1 having arectangular hole of different dimensions.

FIG. 10 is a front elevational view of another collimation plate for usewith the receptor positioning device shown in FIG. 1 having arectangular hole of still different dimensions.

FIG. 11 is a side view of the receptor positioning device shown in FIG.1 depicting the patient's teeth biting the device and the x-ray machinein position.

FIG. 12 is a back plate for receiving receptor of the receptorpositioning device shown in FIG. 1.

FIG. 13 is a side elevational view of the back plate of FIG. 12.

FIG. 14 is another embodiment of a back plate for receiving electronicreceptors of the receptor positioning device shown in FIG. 1, havingopposing notches.

FIG. 15 is a side elevational view of the back plate of FIG. 14.

FIG. 16 is a perspective view of the receptor positioning device of thepresent invention incorporating a digital receptor.

FIG. 17 is a perspective view of an embodiment of the collimation/shielddevice of the present invention, with attachment member, intended foruse with a typical prior art film holding instrument.

FIG. 18 is a rear elevational view of the shield device shown in FIG.17.

FIG. 19 is a front elevational view of the attachment member shown inFIG. 17.

FIG. 20 is a side elevational view of the shield device shown in FIG.17.

FIG. 21 is a top view of the shield device shown in FIG. 17.

FIG. 22 is a top view of the attachment member shown in FIG. 19.

FIG. 23 is a side elevational view of the attachment member shown inFIG. 19.

FIG. 24 is a side elevational view of the clip for the attachment membershown in FIG. 19.

FIG. 25 is a front elevational view of a typical prior art aiming ringwith which the present invention is useful.

FIG. 26 is a cross-sectional view of the aiming ring of FIG. 25, alongline 26-26, showing the insertion of the corner locator tabs of theshield device of FIG. 17 into the index indentations of the aiming ring.

FIG. 27 is a cross-sectional view of the aiming ring of FIG. 25, alongline 27-27, showing the clip attachment of the shield device of FIG. 17.

FIG. 28 is a top plan view of the shield device of FIG. 17 attached to atypical intraoral film holding instrument positioned in the patient'smouth, with the x-ray machine in position.

FIG. 29 is a side elevational view of the shield device shown in FIG. 17attached to a typical intraoral film holding instrument positioned inthe patient's mouth, with the x-ray machine in position.

DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

In describing the preferred embodiment of the present invention,reference will be made herein to FIGS. 1-29 of the drawings in whichlike numerals refer to like features of the invention. Features of theinvention are not necessarily shown to scale in the drawings.

A preferred embodiment 10, shown in FIGS. 1-6 and 11, depicts theintraoral dental radiology receptor positioning device of the presentinvention. Referring to FIGS. 1-4, the receptor positioning deviceincludes a substantially flat collimation plate 12, having a surfacearea 14. The surface area 14 defines a substantially central rectangularopening 16. The collimation plate 12 further includes opposing elongatedhandles 18 extending outward on opposite sides thereof. The receptorpositioning instrument 10 further includes an elongated arm 20 and afilm or electronic receptor holding member 28 having a back plate 30 andclips 32 for holding x ray film or electronic receptors. The elongatedarm 20 is connected at a bent first end 40 to the back of thecollimation plate 50, preferably, by welding or other rigid connection.The elongated arm further includes a second end 22 attached to the rearsurface 52 of the back plate 30 of the receptor holding member 28,opposite collimator plate 12.

The film or electronic receptor holding member 28 back plate 30 ispreferably of metal and the opposing clips 32 are designed and adaptedto receive and grasp a removable film or digital-electronic receptor 54.The elongated arm 20 includes a flat upper surface 26 adapted to receivea patient's teeth. The patient's teeth 60 a on one side of the mouth arepositioned to grip the substantially flat biting surface 26 of theelongated arm 20, as shown in FIG. 3. The biting surface receivingportion is normally incompressible. Optionally, biting surface 26 on arm20, behind the receptor plate 54, includes a plurality of circularperforations or openings, for example the three 6 mm diameter openings70 longitudinally spaced 8 mm apart as shown in FIG. 3. These openingsaccommodate a curable elastomeric impression material 72, on either sideof biting surface 26 (see also FIGS. 4-6, which may be used to createand register with the unique occlusion pattern of the patient's teeth,as also shown in FIG. 11. This registration may be removed, archived andreused to create reproducible x-ray images of the teeth in repeatedsequential exposures over time.

The film or receptor 54 held on the back plate 30 by the clips 32 of thereceptor holding member 28 is positioned behind the desired teeth 60 bto be exposed, on the opposite side of the patient's mouth. Preferably,the back plate 30 and receptor 54 are parallel to collimation plate 12.The film or receptor 54 is thereby positioned to be exposed to an x-rayfrom the x-ray machine 62 to show the condition of teeth 60 b, as shownfurther in FIG. 11.

Referring to FIG. 2, the collimation plate 12 further includes apreferably rectangular opening 200 positioned substantially in thecenter of the collimation plate 12. The opening 16 has a verticaldimension 202, and a horizontal dimension 204. In the preferredembodiment shown in FIGS. 1 and 2, the vertical dimension 202 of theopening is about 1.210 in. (3.1 cm), and the horizontal dimension 204 ispreferably about 1.552 in. (3.9 cm). The collimation plate 12 is adaptedto axially align the x-ray machine's position indicating cylinder device62 with the receptor 54, as shown by the x-ray centerline 63. It doesthis in two ways. First, the x-ray machine is easily centered becausethe two devices, 12, 62, have substantially the same diameter. Axialoffset would be apparent by extension of the outer edge of collimationplate 12 beyond the outer rim of the x-ray machine position indicatingcylinder device 62. Second, substantially full, flat contact of thecollimation plate 12 with the x-ray machine's position indicatingcylinder device 62, as shown in FIG. 3, would assure optimal alignmentof the x-ray receptor with the x-ray beam.

The orientation and size of the rectangular collimation openingdescribed above is for use with the adult size horizontal bitewingradiographic examination of patients with normal anatomy and dentitions.Other sizes may be made for small children or for other uses. Whileexisting commercially available metal collimation plates generally haveon the order of 0.050 in. (1.27 mm) thickness, the inventor's dosimetrystudies have shown that this thickness still permits a substantialamount of radiation to penetrate and expose the patient to needlessadditional radiation. Preferably, the thickness T of the collimationplate (FIG. 4) has at least 0.075 in. (1.9 mm) thickness, morepreferably 0.080 (2.0 mm) or 0.100 in. (2.5 mm) or more to block suchexcess radiation.

Referring to FIGS. 5 and 6, the substantially flat elongated arm 20 ofthe preferred embodiment shown in FIG. 1 is shown including the firstend 40, the second end 22, a short member 23 (on which biting surface 26is located) having a first length 25, and an angled portion 21. FIG. 5shows arm 20 as a flat blank prior to forming at the dotted lines, whileFIG. 6 shows arm 20 after forming, where both ends 22 and 40 are bentapproximately 90° . The second end 22 of the elongated arm 20, and theouter edge of the angled portion 21 define a first dimension 27. Thefirst dimension 27 is preferably about 1.25 in. (3.2 cm), and the firstlength 25 is preferably about 2.54 in. (6.45 cm). The outer edge of theshort member 23 and the vertical plane define an angle 29 whichdetermines the angulation of the short member 23 of the elongated arm20. The preferred angle 29 is about 12° . These dimensions and anglesare preferred for three reasons. First, the dimension of the elongatedarm is consistent with optimal placement of an x-ray receptor in mouthswith normal anatomy and dentitions ranging in size from that of a child(8 years and up) to very large. Second, the dimension of the elongatedarm is compatible with accommodating conventional film anddigital-electronic receptors currently available. Third, the dimensionof the elongated arm is compatible with accommodating the x-raysmachine's position indicating cylinder device in optimal configurationwith the receptor in the patient's mouth.

Referring to FIGS. 7 and 8, another embodiment of an elongated arm 100is shown which can be used with the receptor positioning device 10 shownin FIGS. 1-4. The elongated arm 100 includes the first end 40, thesecond end 22, the angled portion 21, and the short member 23 as in theembodiment shown in FIGS. 5 and 6. Again, FIG. 7 shows arm 20 as a flatblank prior to forming at the dotted lines, while FIG. 8 shows arm 20after forming, where both ends 22 and 40 are bent approximately 90° .However, here the short member has a second length 106 which is morethan the dimension 25 of the embodiment shown in FIGS. 1 and 5-6. Thesecond length 106 is preferably about 2.85 in. (7.2 cm). The second end22 of the elongated arm 20, and the outer edge of the angled portion 21define a second dimension 104 which is less than the first dimension 27of the embodiment shown in FIGS. 1 and 5-6. The second dimension 104 isless than the first dimension shown in FIG. 5 and preferably about 1.10in. (2.8 cm). The outer edge of the short member 23 and the verticalplane define an angle 108 which is less than or more acute than theangle 29 of the embodiment shown in FIGS. 5 and 6 and is preferablyabout 7° . The more acute angle 108 better accommodates deep overbiteocclusions. This other embodiment of the elongated arm has a dimensionthat is easily accommodated in mouths that have anatomy with deepoverbites (retrognathic mandibles) ranging in size from that of a childto a large adult.

Referring to FIGS. 9-10, other embodiments of a collimation plate 12 areshown including opposing elongated handles 18. Referring to FIG. 9, thecollimation plate 12 further includes a preferably rectangular opening210 positioned substantially in the center of the collimation plate 12,where the length of the opening 210 is smaller than the width. Theopening 210 has a vertical dimension 212, and a horizontal dimension214. In this embodiment, the vertical dimension 212 of the opening ispreferably about 1.552 in. (3.9 cm), and the horizontal dimension 214 ispreferably about 1.210 in. (3.1 cm). This embodiment offers a differentpositioning of the opening to correspond to an adult receptor or filmheld in the receptor holding member 28. The orientation and size of therectangular collimation opening is for use with the adult size verticalbitewing radiographic examination. This is useful for observingcompromised dentitions (with large restorations and height of alveolarcrest bone decreased by marginal periodontal disease) that would not bevisualized on horizontal bitewing images.

Referring to FIG. 10, the collimation plate 12 further includes apreferably rectangular opening 220 positioned substantially in thecenter of the collimation plate 12. The opening 220 has a verticaldimension 222, and a horizontal dimension 224. In this embodiment thevertical dimension 222 of the opening is about 1.000 in. (2.5 cm), andthe horizontal dimension 224 is preferably about 1.552 in. (3.9 cm).This embodiment is designed to correspond to a child's receptor or filmheld in the receptor holding member 28. The size and orientation of therectangular collimation opening is for use for horizontal bitewingexaminations in small children (4-8 years) and very small adults oradults with limited ability to open their mouths.

Referring to FIGS. 12 and 13, the back plate 30 is shown of the deviceof FIG. 1. FIG. 12 shows the flat blank for plate 30 and FIG. 13 showsplate 30 after forming. The back plate 30 includes the clips 32 andpreferably has an overall length 36 of about 1.71 in. (4.3 cm), and adimension between the clips 38 of preferably about 1.578 in. (4.0 cm),as they are shown formed and curled in FIG. 13. The preferred dimension34 between the back plate 30 and the formed clip 32 is about 0.05 in.(1.3 mm). The overall length 36 of the back plate 30 with the clips 32curled, as shown in FIG. 13, is preferably about 1.71 in. (4.3 cm), andthe length 38 between the curled clips 32 is preferably about 1.578 in.(4.0 cm). The width 35 of the back plate 30 is preferably about 1.20 in.(3.05 cm). The dimensions herein accommodate standard intraoral dentalfilm.

Referring to FIGS. 14 and 15, another embodiment is shown of the backplate 30. As before, FIG. 14 shows the flat blank for plate 30 and FIG.15 shows plate 30 after forming. The embodiment shown in FIGS. 14 and 15is the same as in the embodiment shown in FIGS. 12 and 13 except in theaddition of two opposing notches 39. These notches are on opposite sidesof the back plate and are on adjacent sides with reference to the clips32. The notches 39 are a specified dimension 31 from the midpoint of thelong side of the back plate 30. The dimension 31 is preferably about0.15 in. (3.8 mm). The notches 39 accept electronic receptors to theback plate 30 of the receptor holding member 28 with the aid oforthodontic elastics (not shown). The overall length 36, the length 38between the curled clips 32, and the width 35 of the back plate 30 isthe same as in the previous embodiment shown in FIGS. 12-13. FIG. 16shows receptor 54 held in place on receptor holding member 28 by a pairof orthodontic elastic bands 76 which are received in two spaced pairsof notches 39. Where the receptor 54 is a digital-electronic receptor,data cord 78 extending from the receptor may be secured to and alongelongated arm 20 by connector 80, between the collimation plate and thereceptor holding member, so that data plug 82 may be positioned outsidethe patient's mouth.

Other back plate sizes may be used, such as one designed for receptorsor film used for children which is smaller than the films used with theback plates shown in FIGS. 12-15. Such a back plate would preferablyhave a length between the curled clips of about 1.60 in. (4.1 cm) longsimilar to the embodiments shown in FIGS. 12-15, but, a width ofpreferably about 1.00 in. (2.5 cm) wide to accommodate size filmdesigned for children.

In operation and use, referring to FIG. 11, the patient's mouth 65 isoutlined and the patient's teeth are above and below the elongated arm20 of the receptor positioning device 10. Teeth 60 a bite down on andgrip biting portion 26 of arm 20. Biting portion 26 may containelastomeric impression material which conforms to the occlusion patternof the patient's teeth 60 a. The receptor holding member 28 ispositioned behind the teeth 60 b to be exposed (on the opposite side ofthe mouth from teeth 60 a) and the collimation plate 12 is positioned inadjacent to the patient's mouth 65 and teeth 60 b. The x-ray machine 62is positioned to take an x-ray in front of the collimation plate 12 andexpose the x-ray film receptor 54. If necessary, the patient orradiographer may use handles 18 to reposition the receptor positioningdevice for better comfort or aim. Preferably the collimation plate 12 isconstructed of a metal and rigidly and fixedly fashioned. The rigid andfixed construction of the receptor positioning device 10 provides themost accurate film exposure because there is minimal opportunity forunwanted movement after positioning the device. The metal collimationplate having a rectangular opening 16 reduces patient exposure byabsorbing approximately 50% of primary beam x-radiation for the mostcommonly prescribed dental radiograph, which is the bitewing. Further,the metal collimation plate reduces aiming error, that is, “cone cuts”,which are frequently associated with the rectangular position-indicatingdevice attached to the x-ray machine. Further, the use of thecollimation plate of the present invention having a rectangular opening16 reduces patient exposure to x-radiation by eliminating needless“retakes” of radiographs. The collimation plate 12 of the presentinvention is compatible with typical round (typically 2.75 in. or 7.0 cmdiameter) indicating cylinder device that is typically standard ondental radiographic machines.

Another advantage of a device of the present invention pertains to theabsorption of x-rays by the metal receptor holding member 28 whichimproves the quality of the acquired image on the film 54. The receptorholding member 28 is preferably constructed of a metal. The metalreceptor holding member 28 will further reduce patient exposure tox-radiation by absorbing x-radiation that would ordinarily pass throughthe receptor or film 54. Also, the metal receptor holding member 28reduces additional secondary or “scatter” radiation that causesdegradation of the image.

As shown in FIGS. 1-16, the unitary design of the receptor positioningdevice 10 eliminates movement of multiple parts which could interferewith the exposure of the film 54. Further, the unitary design sets afixed x-ray source-to-object distance and an object-to-film distance.Another advantage of the unitary design is the maintenance of uniformmagnification and maximization of the sharpness of the acquired image.Another advantage of the receptor positioning device 10 is the preferredall metal design provides a rigid device which is also durable and lendsitself to sterilizing using steam, heat or chemical methods. Moreover,the handles 18 which are part of the collimation plate 12 enables thepatient to handle the device minimizing patient discomfort andmalpositioning.

Another embodiment 310 of the present invention is shown in FIGS. 17-29,which depict a collimation and shielding device substantially aspreviously described, but removably securable to an otherwiseconventional aiming ring of a typical film holding instrument. Theaiming ring is used for assisting in positioning the x-ray machine.Referring to FIGS. 17-21, the collimation/shield device 310 includes asubstantially flat, circular collimation plate 312 having oppositesurface areas 314, 350 which define a substantially central rectangularopening 316 of width 421 and height 422. The preferred collimation plate312 again includes two elongated handles 318, 319, but at substantiallyright angles from one another extending outward on two adjacent sidesthereof. Alternatively, the collimation/shield may have a pair ofhandles 318, 318 a extending outward substantially opposite of oneanother, as shown in FIGS. 1 and 2 of the previous embodiment. Thehandles may extend along a radius of the collimation plate 312, as withhandles 318, 318 a and 319, or the handles may be offset or otherwisenon-radial, as with handles 318′, 319′. The collimation/shield devicepreferably has at least one handle, but may have more than the two shownin the drawing figures.

To enable facile securing to the ring of a receptor positioning device,the collimation/shield instrument further includes an attachment member320 having raised corner tabs and a pair of attachment clips forattaching the shield to a typical film holder aiming ring. Theattachment member 320 is centrally positioned and may be connected at aflat portion 322 of its front surface or edge to the front or rearsurface of the collimator plate, preferably, by welding or other rigidconnection, so that the attachment member is fixedly coupled to thecollimation shield. Instead of being formed separately, the attachmentmember 320 may be formed in one piece with the collimation/shield device310. As described previously, the thickness of the collimation/shield(along with the attachment member) is at least 0.075 in. (1.9 mm)thickness, more preferably 0.080 (2.0 mm) or 0.100 in. (2.5 mm) or moreto block excess radiation.

The surface area of the attachment member preferably defines asubstantially central rectangular opening 338 of the same dimension asrectangular opening 316 of the collimation/shield device. The opening inthe collimation/shield device is oriented similarly and correspondsdimensionally to the film or other receptor to be used in the filmholding instrument. In the preferred embodiment shown in FIGS. 17-19,the horizontal dimension 421 is about 1.500 in. (3.8 cm) and thevertical dimension 371 of the opening is about 1.200 in. (3.05 cm) foruse with the adult size horizontal and vertical bitewing and periapicalexamination of patients with normal anatomy and dentitions. Other sizesmay be made for small adults, children and other uses. For example, avertical dimension of about 1.000 in. (2.54 cm) and a horizontaldimension of about 1.500 in. (3.8 cm) is for use for horizontal bitewingand periapical examination of small children (2-8 years) and very smalladults or adults with a limited ability to open their mouths, and avertical dimension of about 1.063 in. (2.7 cm) and horizontal dimensionof about 1.688 in. (4.29 cm) is useful for observing compromiseddentitions (with large restorations and height of alveolar crest bonedecreased by marginal periodontal disease) that would not be visualizedin horizontal bitewing and large adult periapical images.

Referring in particular to FIGS. 17, 19-24 and 27, the attachment member320 has a pair of opposing spring clips 330 designed and adapted toreceive and grasp the typical aiming ring 372 on a prior art intraoralfilm holder 370 (FIGS. 25, 28 and 29). The preferred overall height 400between the attachment member 320 and the formed clips 330 is about0.375 in. (9.5 mm). The over all length 340 of the attachment member 20with the clips bent is preferably about 2.406 in. (6.1 cm) and thelength 320 between the bent clips 330 is preferably about 2.125 in. (5.4cm), as shown in FIGS. 23 and 24. The preferred length of the clip base450 is about 0.0625 in. (1.6 mm), the preferred angle of bend 421between the clip base and the clip upright portion is about 112° , thepreferred height 410 between the clip base and shoulder is about 0.125in. (3.2 mm), and the preferred projection 441 of the shoulder is about0.0625 in. (1.6 mm). Clips 330 engage the inner periphery of aiming ring372 (FIG. 25) in order to removably secure the attachment member 320 andcollimation plate 312 to the ring. This is done by flexing or bendingthe clips inward, toward each other in direction 415 (FIG. 27), andinserting them into the aiming ring opening. When released, the clipsare urged outward by their spring action and secure thecollimation/shield device 310 in place over aiming ring 372.

The preferred attachment member 320 also includes four raised cornerstabs 326 to align with the index indentations 373 of film holding aimingring 372 (FIGS. 25 and 26). The pair of recesses in each indexindentation 373 permits different orientation of the collimation/shielddevice. The raised corner tabs are disposed at the corners of thesubstantially rectangular attachment member 320, and have dimensions 370and 371, as shown in FIG. 19. The preferred dimension 371 is about1.1875 in. (3.0 cm) and the preferred dimension 370 is about 1.563 in.(3.9 cm). In this embodiment, the raised corner tabs 326 have a edgewidth 480 of about 0.185 in. (4.8 mm) and have a rise dimension 429 ofabout 0.0625 in. (1.6 mm). The corner tabs are each delineated by anotch 324 of a preferred dimension 425 of about 0.25 in. (6.35 mm) andan angle of 45° relative to each side of the attachment member. Whencollimation/shield device 310 is clipped to the aiming ring, the cornertabs fit into the index indentations 373 of aiming ring 372, as shown inFIG. 26, to locate and prevent rotation of the collimation/shield devicerelative to the aiming ring. The indentations also permit vertical orhorizontal orientation of the substantially rectangular central openingby rotating the shield device 90° prior to attaching to the aiming ringof a typical film holding instrument, thereby providing positiveorientation in two positions.

Referring to FIGS. 28 and 29, in operation and use, thecollimation/shield device 310 is preferably first clipped to the aimingring 372. Then the plastic biting portion 376, secured to the filmholding instrument 370 by connector 374, is inserted into the patient'smouth 65. The patient's teeth 60 a to be x-rayed rest on and bite on thebiting portion. The receptor holding member 378 of the biting portion376 is positioned behind the teeth 60 a to be exposed and the aimingring 372 with the attached shield device 310 is positioned adjacent tothe patient's mouth 65 and teeth 60 a. The x-ray machine 63 ispositioned to take an x-ray in front of the shield device 10 and exposethe x-ray film 354. Preferably the collimation/shield device 310 isconstructed of metal and rigidly and fixedly fashioned for preciseattachment to the typical aiming ring. The patient or radiographergrasps the handles 318, 319 to position and maintain the film holdinginstrument in the optimal aimed position with better comfort

As described previously, and as shown in FIGS. 28 and 29, collimationplate 312 is adapted to axially align the x-ray machine's positionindicating cylinder device 62 with the receptor 354 shown by the x-raycenter line the 63. It does this in two ways. First, the x-ray machineis easily centered because preferably the two devices 312, 62 havesubstantially the same diameter. Axial offset would be apparent byextension of the outer rim of the x-ray machine position indicatingcylinder device 62. Second, substantially full, flat contact of thecollimation plate 312 with the x-ray machine's position indicatingcylinder device 62, as shown in FIGS. 28 and 29, would assure optimalalignment of the x-ray receptor with the x-ray beam.

The rigid and fixed construction of the shield device 310 provides themost accurate film exposure because there is minimal opportunity forunwanted movement after positioning the device. The metalcollimation/shield device having the rectangular opening reduces patientexposure by absorbing approximately 50% of the primary beam x-radiationfor most commonly prescribed dental intraoral radiographs, which are thebitewing and periapical views. As with the previous embodiments, themetal collimation/shield device of FIGS. 17-29 reduces aiming error, orcone cuts, and eliminates needless retakes of radiographs for typicalprior art film holding instruments.

The collimation/shield device 310 of the present invention is compatiblewith a round indicating cylinder device 62 of 2.75 in. (7.0 cm) diameterthat is typically standard on dental radiographic machines and with theround aiming ring 372 of 2.75 in. (7.0 cm) diameter that is a componentof a typical intraoral film holder 70. The unitary design of the shielddevice 10 permits precise attachment to the typical aiming ring 372,thus, preventing additional movement that could interfere with theexposure of the film 54. Another advantage of the collimation/shielddevice is that, prior to attaching, the orientation of the centralopening 316 of the shield can be rotated 90° relative to the aiming ringand selected film holding member of typical receptor positioninginstruments, thus, permitting vertical or horizontal orientation.Another advantage of the collimation/shield device 310 is the preferredall metal design provides a rigid device which is also durable and lendsitself to sterilization using steam, heat or chemical methods. Moreover,the handles 318, 319 which are part of the collimation/shield device 310enable the patient to handle the device minimizing patient discomfortand malpositioning.

While the present invention has been particularly described, inconjunction with a specific preferred embodiment, it is evident thatmany alternatives, modifications and variations will be apparent tothose skilled in the art in light of the foregoing description. It istherefore contemplated that the appended claims will embrace any suchalternatives, modifications and variations as falling within the truescope and spirit of the present invention.

1. A receptor positioning device for taking dental bitewing radiographsof a patient's teeth, which comprises: a receptor holding member adaptedto receive a receptor for exposing x-radiation from the x-ray machine;an aiming ring for assisting in positioning the x-ray machine; an armsecured between the aiming ring and the receptor holding member, the armincluding a biting surface for engaging the patient's teeth to securethe device in the patient's mouth; and a collimation plate, secured tothe aiming ring, having a substantially flat surface for aligning withan x-ray machine, an opening in the plate surface for passage ofradiation from the x-ray machine to expose a receptor in the receptorholding member, and a handle extending away from the plate forpositioning the device, the collimation plate being constructed of metalhaving a thickness of at least 0.075 in. to reduce the passage ofradiation from the x-ray machine to the patient except at the plateopening.
 2. The device of claim 1 wherein the collimation plate isremovably secured to the aiming ring.
 3. The device of claim 1 includinga pair of handles extending from the collimation plate at approximatelya right angle to each other.
 4. The device of claim 1 wherein the devicefurther includes a receptor for exposing x-radiation from the x-raymachine and wherein the opening in the collimation plate corresponds indimension to the receptor to reduce overexposure of the patient.
 5. Thedevice of claim 1 wherein the collimation plate further includes clipsfor removably securing the plate to the aiming ring.
 6. The device ofclaim 1 wherein the aiming ring includes notches and the collimationplate further includes tabs for locating the plate relative to theaiming ring notches.
 7. The device of claim 1 wherein the aiming ringincludes notches and the collimation plate further includes clips forremovably securing the plate to the aiming ring and tabs for locatingthe plate relative to the aiming ring notches.
 8. A method for takingdental bitewing radiographs of a patient's teeth comprising: providing areceptor positioning device including a receptor holding member adaptedto receive a receptor for exposing x-radiation from the x-ray machine;an aiming ring for assisting in positioning the x-ray machine; an armsecured between the aiming ring and the receptor holding member, the armincluding a biting surface for engaging the patient's teeth to securethe device in the patient's mouth; and a collimation plate, secured tothe aiming ring, having a substantially flat surface, an opening in theplate surface, and a handle extending away from the plate, thecollimation plate being constructed of metal having a thickness of atleast 0.075 in.; providing a receptor on the receptor holding member;positioning the receptor holding member in the patient's mouth and thepatient's teeth on the biting surface to secure the device in thepatient's mouth; adjusting the position of receptor positioning deviceby grasping the handle extending from the collimation plate; aligning anx-ray machine with the substantially flat surface of the collimationplate; and passing radiation from the x-ray machine through the openingof the collimation plate while substantially blocking passage ofradiation through the collimation plate thickness to expose thereceptor.
 9. The method of claim 8 wherein the device includes a pair ofhandles extending from the collimation plate at approximately a rightangle to each other, and including grasping the handles to adjust theposition of receptor positioning device.
 10. The method of claim 8wherein the opening in the collimation plate corresponds in dimension tothe receptor to reduce overexposure of the patient to the radiation. 11.The method of claim 8 wherein the device further includes an aiming ringsecured to the arm at a position distal from the receptor holdingmember, and further including securing the collimation plate to theaiming ring.
 12. The method of claim 8 wherein the collimation plateincludes clips for removably securing the plate to the aiming ring, andfurther including bending the clips to secure the collimation plate tothe aiming ring.
 13. The method of claim 8 wherein the aiming ringincludes notches and the collimation plate further includes tabs forlocating the plate relative to the aiming ring, and further includinginserting the collimation plate tabs into the aiming ring notches. 14.The method of claim 8 wherein the aiming ring includes notches and thecollimation plate includes clips for removably securing the plate to theaiming ring and tabs for locating the plate relative to the aiming ring,and further including bending the clips to secure the collimation plateto the aiming ring and inserting the collimation plate tabs into theaiming ring notches.
 15. A method for taking dental bitewing radiographsof a patient's teeth comprising: providing a receptor positioning deviceincluding a receptor holding member adapted to receive a receptor forexposing x-radiation from the x-ray machine; and an aiming ring forassisting in positioning the x-ray machine; an arm secured between theaiming ring and the receptor holding member, the arm including a bitingsurface for engaging the patient's teeth to secure the device in thepatient's mouth; providing a collimation plate having a substantiallyflat surface, an opening in the plate surface, and a handle extendingaway from the plate, the collimation plate being constructed of metalhaving a thickness of at least 0.075 in.; providing a receptor on thereceptor holding member, the receptor corresponding in dimension to thecollimation plate opening; securing the collimation plate to the aimingring; positioning the receptor holding member in the patient's mouth andthe patient's teeth on the biting surface to secure the device in thepatient's mouth; adjusting the position of receptor positioning deviceby grasping the handle extending from the collimation plate; aligning anx-ray machine with the substantially flat surface of the collimationplate; and passing radiation from the x-ray machine through the openingof the collimation plate while substantially blocking passage ofradiation through the collimation plate thickness to expose the receptorand to reduce overexposure of the patient to the radiation.
 16. Themethod of claim 15 wherein the device includes a pair of handlesextending from the collimation plate at approximately a right angle toeach other, and including grasping the handles to adjust the position ofreceptor positioning device.
 17. The method of claim 15 wherein thedevice further includes an aiming ring secured to the arm at a positiondistal from the receptor holding member, and further including securingthe collimation plate to the aiming ring.
 18. The method of claim 15wherein the collimation plate includes clips for removably securing theplate to the aiming ring, and further including bending the clips tosecure the collimation plate to the aiming ring.
 19. The method of claim15 wherein the aiming ring includes notches and the collimation platefurther includes tabs for locating the plate relative to the aimingring, and further including inserting the collimation plate tabs intothe aiming ring notches.
 20. The method of claim 15 wherein the aimingring includes notches and the collimation plate includes clips forremovably securing the plate to the aiming ring and tabs for locatingthe plate relative to the aiming ring, and further including bending theclips to secure the collimation plate to the aiming ring and insertingthe collimation plate tabs into the aiming ring notches.